Exposure apparatus, manufacturing method of flat-panel display, device manufacturing method, and exposure method

ABSTRACT

A liquid crystal exposure apparatus is equipped with: a substrate holder that is disposed below a projection optical system and holds a substrate; a first drive section that moves the substrate holder along an XY plane; heads that measures the position information of the substrate holder; head stages that support the heads and are movable within the XY plane; and a second drive section that moves the head stages in the X-axis direction and the Y-axis direction, and the second drive section moves the head stages in the X-axis direction or the Y-axis direction when the substrate holder is moved in the X-axis direction or the Y-axis direction by the first drive section.

TECHNICAL FIELD

The present invention relates to exposure apparatuses, manufacturingmethods of flat-panel displays, device manufacturing methods andexposure methods, and more particularly to an exposure apparatus and anexposure method to expose an object with an illumination light, and amanufacturing method of flat-panel displays or a device manufacturingmethod using the exposure apparatus.

BACKGROUND ART

Conventionally, in a lithography process for manufacturing electronicdevices (microdevices) such as liquid crystal display devices andsemiconductor devices (integrated circuits and the like), used areexposure apparatuses such as an exposure apparatus of a step-and-scanmethod (a so-called scanning stepper (which is also called a scanner))that, while synchronously moving a mask (a photomask) or a reticle(hereinafter, generically referred to as a “mask”) and a glass plate ora wafer (hereinafter, generically referred to as a “substrate”) along apredetermined scanning direction (scan direction), transfers a patternformed on the mask onto the substrate using an energy beam.

As this type of exposure apparatuses, such an exposure apparatus isknown that is equipped with an optical interferometer system thatobtains the position information of a substrate serving as an exposuretarget, within a horizontal plane, using a bar mirror (a long mirror)that a substrate stage device has (e.g., refer to PTL 1).

Here, in the case of obtaining the position information of a substrateusing the optical interferometer system, the influence of so-called airfluctuation cannot be ignored. Further, although the influence of airfluctuation can be reduced by using an encoder system, it is difficultto prepare a scale that can cover the entire movement range of thesubstrate due to the increase in size of the substrate in recent years.

CITATION LIST Patent Literature

[PTL 1] U.S. Patent Application Publication No. 2010/0266961

SUMMARY OF INVENTION

According to a first aspect of the present invention, there is providedan exposure apparatus that exposes an object with an illumination lightvia a projection optical system, the apparatus comprising: a firstmovable body that is disposed below the projection optical system, andholds the object; a first drive section that moves the first movablebody in a first direction and a second direction that are orthogonal toeach other within a predetermined plane orthogonal to an optical axis ofthe projection optical system; a measurement section that measuresposition information of the first movable body; and a second movablebody that supports the measurement section and is movable within thepredetermined plane; and a second drive section that moves the secondmovable body in the first and the second directions, wherein the seconddrive section moves the second movable body in the first direction orthe second direction when the first movable body is moved in the firstdirection or the second direction by the first drive section.

According to a second aspect of the present invention, there is provideda manufacturing method of a flat-panel display, comprising: exposing theobject using the exposure apparatus related to the first aspect; anddeveloping the object that has been exposed.

According to a third aspect of the present invention, there is provideda device manufacturing method, comprising: exposing the object using theexposure apparatus related to the first aspect; and developing theobject that has been exposed.

According to a fourth aspect of the present invention, there is providedan exposure method of exposing an object with an illumination light viaa projection optical system, the method comprising: moving a firstmovable body in a first direction and a second direction by a firstdrive section, the first movable body being disposed below theprojection optical system and holding the object, and the first and thesecond direction being orthogonal to each other within a predeterminedplane orthogonal to an optical axis of the projection optical system;measuring position information of the first movable body by ameasurement section; moving a second movable body in the first and thesecond directions by a second drive section, the second movable bodysupporting the measurement section and being movable within thepredetermined plane; and moving the second movable body in the firstdirection or the second direction by the second drive section when thefirst movable body is moved in the first direction or the seconddirection by the first drive section.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a view schematically showing the configuration of a liquidcrystal exposure apparatus related to a first embodiment.

FIG. 2 is a concept view of a mask encoder system and a substrateencoder system equipped in the liquid crystal exposure apparatus shownin FIG. 1.

FIG. 3A is a plan view showing the configuration of the mask encodersystem, and FIG. 3B is a plan view showing the configuration of thesubstrate encoder system.

FIG. 4A is an enlarged view of an A-part of FIG. 3A, FIG. 4B is anenlarged view of a B-part of FIG. 3B, and FIG. 4C is an enlarged view ofa C-part of FIG. 3B.

FIGS. 5A to 5E are views (No. 1 to No. 5) used to explain the linkageprocessing of head outputs in the mask encoder system and the substrateencoder system.

FIG. 6 is a block diagram showing the input/output relationship of amain controller that centrally configures a control system of the liquidcrystal exposure apparatus.

FIGS. 7A and 7B are views (No. 1 and No. 2) used to explain theoperations of the substrate encoder system at the time of exposureoperation.

FIG. 8 is a view showing the configuration of a substrate encoder systemrelated to a second embodiment.

FIG. 9 is a view used to explain the configuration of a measurementsystem for obtaining the distance between a pair of heads.

FIG. 10 is a view used to explain the configuration of a measurementsystem for obtaining a tilt amount of a head stage.

FIG. 11 is a concept view of the mask encoder system and the substrateencoder system equipped in the liquid crystal exposure apparatus shownin FIG. 1.

DESCRIPTION OF EMBODIMENTS First Embodiment

A first embodiment will be described below, using FIGS. 1 to 7.

FIG. 1 schematically shows the configuration of a liquid crystalexposure apparatus 10 related to the first embodiment. Liquid crystalexposure apparatus 10 is a projection exposure apparatus of astep-and-scan method, which is a so-called scanner, with a rectangular(square) glass substrate P (hereinafter, simply referred to as asubstrate P) used in, for example, a liquid crystal display device (aflat-panel display) or the like, serving as an object to be exposed.

Liquid crystal exposure apparatus 10 has: an illumination system 12; amask stage device 14 to hold a mask M on which a circuit pattern and thelike are formed; a projection optical system 16; an apparatus main body18; a substrate stage device 20 to hold substrate P whose surface (asurface facing the +Z side in FIG. 1) is coated with resist (sensitiveagent); a control system thereof; and the like. Hereinafter, theexplanation is given assuming that a direction in which mask M andsubstrate P are each scanned relative to projection optical system 16 atthe time of exposure is an X-axis direction, a direction orthogonal tothe X-axis within a horizontal plane is a Y-axis direction, and adirection orthogonal to the X-axis and the Y-axis is a Z-axis direction,and rotation directions around the X-axis, the Y-axis and the Z-axis area θx direction, a θy direction and a θz direction, respectively.Further, the explanation is given assuming that the positions in theX-axis direction, the Y-axis direction and the Z-axis direction are anX-position, a Y-position and a Z-position, respectively.

Illumination system 12 is configured similarly to an illumination systemdisclosed in, for example, U.S. Pat. No. 5,729,331 and the like.Illumination system 12 irradiates mask M with light emitted from a lightsource (not illustrated) (e.g. a mercury lamp), as illumination lightfor exposure (illumination light) IL, via a reflection mirror, adichroic mirror, a shutter, a wavelength selecting filter, various typesof lenses and the like (none of which are illustrated). As illuminationlight IL, light such as, for example, an i-line (with a wavelength of365 nm), a g-line (with a wavelength of 436 nm), and an h-line (with awavelength of 405 nm) (or synthetic light of the i-line, the g-line andthe h-line described above) is used.

Mask stage device 14 includes: a mask holder 40 that holds mask M by,for example, vacuum adsorption; a mask driving system 48 (notillustrated in FIG. 1, see FIG. 6) for driving mask holder 40 with apredetermined long stroke in the scanning direction (the X-axisdirection), and also finely driving mask holder 40 in the Y-axisdirection and the θz direction as needed; and a mask encoder system 50for obtaining the position information within the XY plane (includingalso rotation amount information in the θz direction, the same applyinghereinafter) of mask holder 40. Mask holder 40 is made up of aframe-like member in which an opening section with a rectangular shapein planar view is formed, as disclosed in, for example, U.S. PatentApplication Publication No. 2008/0030702. Mask holder 40 is placed, forexample, via air bearings (not illustrated), on a pair of mask guides 42fixed to an upper mount section 18 a that is a part of apparatus mainbody 18. Mask driving system 48 includes, for example, a linear motor(not illustrated). The configuration of mask encoder system 50 will bedescribed in detail later.

Projection optical system 16 is disposed below mask stage device 14.Projection optical system 16 is a so-called multi-lens type projectionoptical system having a configuration similar to a projection opticalsystem disclosed in, for example, U.S. Pat. No. 6,552,775 and the like,and projection optical system 16 is equipped with a plurality (e.g.eleven in the present embodiment, see FIG. 3A) of optical systems thatare, for example, both-side telecentric unmagnification systems, andform erected normal images.

In liquid crystal exposure apparatus 10, when an illumination area onmask M is illuminated with illumination light IL from illuminationsystem 12, by the illumination light that has passed through mask M, aprojected image (a partial erected image) of a circuit pattern of mask Mwithin the illumination area is formed, via projection optical system16, on an irradiation area (an exposure area) of the illumination light,on substrate P, that is conjugate with the illumination area. Then, maskM is moved relative to the illumination area (illumination light IL) inthe scanning direction and also substrate P is moved relative to theexposure area (illumination light IL) in the scanning direction, andthereby the scanning exposure of one shot area on substrate P isperformed and the pattern formed on mask M is transferred onto the shotarea.

Apparatus main body 18 supports mask stage device 14 and projectionoptical system 16 described above, and is installed on a floor 11 of aclean room via a plurality of vibration isolating devices 19. Apparatusmain body 18 is configured similarly to an apparatus main body asdisclosed in, for example, U.S. Patent Application Publication No.2008/0030702, and apparatus main body 18 has: upper mount section 18 a,a lower mount section 18 b and a pair of middle mount sections 18 c.Since projection optical system 16 described above is supported by uppermount section 18 a, hereinafter the explanation is given referring toupper mount section 18 a as an “optical surface plate 18 a” as needed.

Substrate stage device 20 is a device for performing the high accuracypositioning of substrate P relative to projection optical system 16(illumination light IL), and substrate stage device 20 drives substrateP with a predetermined long stroke along the horizontal plane (theX-axis direction and the Y-axis direction), and also finely drivessubstrate P in directions of six degrees of freedom. Although theconfiguration of substrate stage device 20 is not particularly limited,it is preferable to use a stage device having a so-called coarse-finemovement configuration that includes a gantry type two-dimensionalcoarse movement stage and a fine movement stage that is finely drivenrelative to the two-dimensional coarse movement stage, as disclosed in,for example, U.S. Patent Application Publication No. 2008/0129762 orU.S. Patent Application Publication No. 2012/0057140, and the like.

Substrata stage device 20 is equipped with a substrate holder 24.Substrate holder 24 is made up of a plate-like member with a rectangularshape in planar view, and substrate P is placed on the upper surface ofsubstrate holder 24. Substrate holder 24 is driven with a predeterminedlong stroke relative to projection optical system 16 in the X-axisdirection and/or the Y-axis direction and also finely driven in thedirections of six degrees of freedom, by a plurality of linear motors(e.g. voice coil motors) that configure a part of substrate drivingsystem 28 (not illustrated in FIG. 1, see FIG. 6).

Further, liquid crystal exposure apparatus 10 has a substrate positionmeasurement system for obtaining the position information of substrateholder 24 (i.e. substrate P) in the directions of six degrees offreedom. As illustrated in FIG. 6, the substrate position measurementsystem includes a Z-tilt position measurement system 88 for obtainingthe position information of substrate P in the Z-axis direction, the exdirection and the θy direction (hereinafter, referred to as Z-tiltdirections), and a substrate encoder system 60 for obtaining theposition information of substrate P within the XY plane. Although theconfiguration of Z-tilt position measurement system 88 is notparticularly limited, such a measurement system can be used that obtainsthe position information of substrate P in the Z-tilt directions withapparatus main body 18 (e.g. lower mount section 18 b) serving as areference, using a plurality of sensors attached to a system includingsubstrate holder 24, as disclosed in, for example, U.S. PatentApplication Publication No. 2010/0018950. The configuration of substrateencoder system 60 will be described later.

Next, the concept of mask encoder system 50 and substrate encoder system60 in the present embodiment will be described using FIG. 2. As shown inFIG. 2, mask encoder system 50 obtains the position information of maskholder 40 with optical surface plate 18 a (projection lenses) serving asa reference. Also, substrate encoder system 60 obtains the positioninformation of substrate P with optical surface plate 18 a (projectionlenses) serving as a reference.

Mask encoder system 50 has a head stage 54 to which a plurality ofencoder heads (hereinafter, simply referred to as “heads”) 58L and 58Sare attached. Head stage 54 is movable with a long stroke relative tooptical surface plate 18 a in the X-axis direction, synchronously withthe movement of mask stage device 14 holding mask M. The positioninformation of head stage 54 is obtained by a long encoder system thatincludes head 58L referred to above and an encoder scale 56L(hereinafter, referred to as a long scale 56L (a diffraction gratingplate)) fixed to optical surface plate 18 a. Further, the relativeposition information between head stage 54 and mask holder 40 isobtained by a short encoder system that includes head 58S referred toabove and an encoder scale 56S (hereinafter, referred to a short scale56S (a diffraction grating plate)) fixed to mask holder 40. Mask encodersystem 50 obtains the position information of mask holder 40 withoptical surface plate 18 a serving as a reference, on the basis of theoutput of the long encoder system referred to above and the output ofthe short encoder system referred to above. Note that the length of longscale 56L in the X-axis direction is longer than the length of shortscale 56X in the X-axis direction. In other words, when comparing thelength of long scale 56L in its longitudinal direction and the length ofshort scale 56S in its longitudinal direction, a scale whose length inthe longitudinal direction is longer is referred to as long scale 56Land a scale whose length in the longitudinal direction is shorter isreferred to as short scale 56S. Similarly, also in the substrate encodersystem to be described later, the length of each of long scales 66X and66Y in its longitudinal direction is longer than the length of a shortscale 66S in its longitudinal direction.

Similarly, substrate encoder system 60 also has a head stage 64 to whicha plurality of heads 68S and 68X are attached. Head stage 64 is movablewith a long stroke relative to optical surface plate 18 a in the X-axisdirection and the Y-axis direction, synchronously with the movement ofsubstrate stage 20 that moves substrate holder 24 on which substrate Pis placed. The position information of head stage 64 is obtained by along encoder system that includes head 68X referred to above, long scale66Y (a diffraction grating plate) fixed to optical surface plate 18 a,and the like. Further, the relative position information between headstage 64 and substrate holder 24 is obtained by a short encoder systemthat includes head 68S referred to above and short scale 66S (adiffraction grating plate) fixed to substrate holder 24. Substrateencoder system 60 obtains the position information of substrate holder24 with optical surface plate 18 a serving as a reference, on the basisof the output the long encoder system referred to above and the outputof the short encoder system referred to above.

Next, a specific example of mask encoder system 50 will be described. Asillustrated in FIG. 1, a pair of encoder bases 52 are fixed on the uppersurface of optical surface plate 18 a. Encoder base 52 is made up of amember extending in the X-axis direction. On the upper surface of eachof the pair of encoder bases 52, a plurality of long scales 56L(overlapping in a depth direction of the page surface in FIG. 1, seeFIG. 3A) are fixed. Further, on the lower surface of mask holder 40, apair of short scales 56S are fixed, corresponding to the pair of encoderbases 52 described above. Further, a pair of head stages 54 are disposedbetween encoder bases 52 and mask holder 40, corresponding to the pairof encoder bases 52 described above.

As illustrated in FIG. 3A, a plurality of long scales 56L are fixed onthe upper surface of encoder base 52. As illustrated in FIG. 4A, theplurality of long scales 56L are disposed at a predetermined spacing inthe X-axis direction. Each of long scales 56L is made up of a plate-like(band-like) member that is formed of, for example, a quartz glass andhas a rectangular shape in planar view extending in the X-axisdirection. Encoder base 52 is formed of a material with a thermalexpansion coefficient lower than (or equal to) that of long scale 56L sothat the grating pitch is prevented from changing due to, for example,the change in temperature and the like.

An X scale 56Lx is formed in an area on one side (the Y side in FIG. 4A)in a width direction of long scale 56L, and a Y scale 56Ly is formed inan area on the other side (the +Y side in FIG. 4A) in the widthdirection. X scale 56Lx is configured of a reflective diffractiongrating (an X grating) having a plurality of grid lines formed at apredetermined pitch in the X-axis direction (with the X-axis directionserving as a period direction) and extending in the Y-axis direction.Similarly, Y scale 56Ly is configured of a reflective diffractiongrating (a Y grating) having a plurality of grid lines formed at apredetermined pitch in the Y-axis direction (with the Y-axis directionserving as a period direction) and extending in the X-axis direction. InX scale 56Lx and Y scale 56Ly of the present embodiment, the pluralityof grid lines are formed with a spacing of, for example, 10 nm or less.Note that, in FIG. 4A, the spacing (the pitch) between the grid lines isillustrated remarkably wider than the actual one, for the sake ofconvenience in illustration. The same applies to the other drawings.

Referring back to FIG. 3A, the pair of short scales 56S are each fixedon the lower surface of mask holder 40. Short scale 56S is configuredsimilarly to long scale 56L except that the length in the X-axisdirection of short scale 56S is shorter than that of long scale 56L.That is, also in short scale 56S, an X scale 56Sx and a Y scale 56Sy areformed in an area on one side and an area on the other side in a widthdirection, respectively. Note that, although the plurality of grid linesare illustrated in solid lines and short scale 56S is illustrated as iffacing upward in FIG. 4A, the plurality of short scales 56S are disposedwith the grating surfaces facing downward in actuality as illustrated inFIG. 1. Further, although short scale 56S is disposed slightly shiftedwith respect to long scale 56L in the Y-axis direction in the presentembodiment, short scale 56S may be disposed at the same Y position aslong scale 56L. Similarly to encoder base 52 described above, maskholder 40 is also formed of a material with a thermal expansioncoefficient lower than (or equal to) that of short scales 56S.

As illustrated in FIG. 4A, head stage 54 is made up of a plate-likemember with a rectangular shape in planar view, and is driven,synchronously with mask holder 40, with a long stroke in the X-axisdirection by a head stage driving system 82 (see FIG. 6) including anactuator such as, for example, a liner motor. Further, mask stage device14 (see FIG. 1) has, for example, a mechanical linear guide device forstraightly guiding head stage 54 in the X-axis direction.

A pair of X long heads 58Lx and a pair of Y long heads 58Ly(collectively referred to as long heads 58L, as needed) are fixed tohead stage 54. Long heads 58L are encoder heads of a so-calleddiffraction interference method, like those disclosed in, for example,U.S. Patent Application Publication No. 2008/0094592, and supply theposition information (or the displacement amount information) of headstage 54 to a main controller 90 (see FIG. 6), by irradiating longscales 56L with measurement beams and receiving the beams from thescales.

That is, in mask encoder system 50, for example, the four X long heads(58Lx×2, 58Lx×2) and X long scales 56Lx (which differ depending on theX-position of head stage 54) that face these X long heads configure, forexample, four X long linear encoders 92Lx (see FIG. 6) for obtaining theposition information of head stage 54 in the X-axis direction, and forexample, the four Y long heads (58Ly×2, 58Ly×2) and Y long scales 56Ly(which differ depending on the X-position of head stage 54) that facethese Y long heads configure, for example, four Y long linear encoders92Ly (see FIG. 6) for obtaining the position information of head stage54 in the Y-axis direction

Main controller 90 obtains the position information of head stage 54(see FIG. 4A) in the X-axis direction and the Y-axis direction with, forexample, a resolution of 10 nm or less, on the basis of the outputs of,for example, the four X long linear encoder 92Lx and, for example, thefour Y long linear encoders 92Ly, as illustrated in FIG. 6. Further,main controller 90 obtains the θz position information (the rotationamount information) of head stage 54, on the basis of the outputs of atleast two of, for example, the four X long linear encoders 92Lx (or, forexample, the four Y long linear encoders 92Ly).

Further, one X short head 58Sx and one Y short head 58Sy (collectivelyreferred to as short heads 58S, as needed) are fixed to head stage 54.Short heads 58S are also encoder heads of a so-called diffractioninterference method, similar to long heads 58L described above, andsupply the relative position information between mask holder 40 and headstage 54 to main controller 90 (see FIG. 6), by irradiating short scales56S with measurement beams and receiving the beams from the scales.

That is, in mask encoder system 50, for example, the two X short heads(58Sx) and X short scale 56Sx that faces these X short heads configure,for example, two X short linear encoders 92Sx (see FIG. 6) for obtainingthe relative position information between mask holder 40 and head stage54 in the X-axis direction, and for example, the two Y short heads(58Sy) and Y short scale 56Sy that faces these Y short heads configure,for example, two Y short linear encoders 92Sy (see FIG. 6) for obtainingthe position information of head stage 54 in the Y-axis direction.

Consequently, head stage driving system 82 (see FIG. 6) described aboverelatively drives mask holder 40 and head stage 54 synchronously withmask holder 40 so that the measurement beams from short heads 58S areprevented from moving off from short scales 56S (so that short heads 58Sfollow short scales 56S). In other words, unless the measurement beamsfrom short heads 58S move off from short scales 56S, the positions ofmask holder 40 and head stage 54 at the time of movement do not have tocompletely coincide with each other. That is, in mask encoder system 50,a configuration is employed in which the relative positional shiftbetween mask holder 40 and head stage 54 is allowed (the positionalshift is compensated) by X short linear encoders 92Sx and Y short linearencoders 92Sy (see FIG. 6).

Here, as is described above, a plurality of long scales 56L are disposedspaced apart at a predetermined spacing in the X-axis direction onencoder base 52 (see FIG. 4A). And, a spacing between a pair of X longheads 58Lx and a spacing between a pair of Y long heads 58Ly that headstage 54 has are each set wider than a spacing between long scales 56Ladjacent to each other. Further, the spacing between a pair of X longheads 58Lx and the spacing between a pair of Y long heads 58Ly are eachset not equal to the length of long scale 56L. Accordingly, in maskencoder system 50, at least one of the pair of X long heads 58Lxconstantly faces X long scale 56Lx, and at least one of the pair of Ylong heads 58Ly constantly faces Y long scale 56Ly. Consequently, maskencoder system 50 can supply the position information of head stage 54to main controller 90 (see FIG. 6) without interruption.

Specifically, for example, in the case where head stage 54 is moved tothe −X side, mask encoder system 50 undergoes transition in the order ofthe following states: a first state (a state illustrated in FIG. 4A)where both of the pair of X long heads 58Lx face long scale 56Lx on the+X side of a pair of long scales 56Lx adjacent to each other; a secondstate where X long head 58Lx on the −X side faces an area between theforgoing pair of X long scales 56Lx adjacent to each other (does notface any one of X long heads 56Lx) and X long head 58Lx on the +X sidefaces the foregoing X long scale 56Lx on the +X side; a third statewhere X long head 58Lx on the −X side faces X long scale 56Lx on the −Xside and also X long head 58Lx on the +X side faces X long scale 56Lx onthe +X side; a fourth state where X long head 58Lx on the −X side facesX long scale 56Lx on the −X side and X long head 58Lx on the +X sidefaces an area between the pair of X long scales 56Lx (does not face anyone of X long scales 56Lx); and a fifth state where both of the pair ofX long heads 58Lx face X long scale 56Lx on the −X side. Consequently,at least one of X long heads 58Lx constantly faces X long scale 56Lx.

Main controller 90 (see FIG. 6) obtains the X-position information ofhead stage 54 on the basis of, for example, the average value of theoutputs of the pair of X long heads 58Lx in the first state, the thirdstate and the fifth state described above. Further, main controller 90obtains the X-position information of head stage 54 on the basis of onlythe output of X long head 58Lx on the +X side in the second statedescribed above, and obtains the X-position information of head stage 54on the basis of only the output of X long heads 58Lx on the −X side inthe fourth state described above. Consequently, the measurement valuesof mask encoder system 50 are not interrupted.

To be more detailed, in mask encoder system 50 of the presentembodiment, in order to prevent the measurement values of mask encodersystem 50 from being interrupted, the linkage processing of the outputsof the heads is performed, when the transition is made between: thefirst, the third and the fifth states described above, i.e., the stateswhere both of the pair of heads face the scale(s) and the output issupplied from each of the pair of heads; and the second and the fourthstates described above, i.e., the states where only one of the pair ofheads faces the scale and the output is supplied from the only one head.The linkage processing of the heads will be described below, using FIGS.5A and 5E. Note that, for the sake of simplified explanation, atwo-dimensional grating (a grating) is assumed to be formed on longscale 56L in FIGS. 5A to 5E. Further, the respective outputs of longheads 58Lx and 58Ly are assumed to have the ideal values. Further, inthe description below, although the linkage processing regarding a pairof X long heads 58Lx adjacent to each other (hereinafter, referred to asX heads 58Lx₁ and 58Lx₂) will be described, the similar linkageprocessing is also performed between a pair of Y long heads 58Lyadjacent to each other (hereinafter, referred to as Y heads 58Ly₁ and58Ly₂),

As illustrated in FIG. 5A, in the case where, of a pair of long scales56L adjacent to each other (hereinafter, referred to as scales 56L₁ and56L₂), each of the pair of X heads 58Lx₁ and 58Lx₂ obtains theX-position information of head stage 54 (see FIG. 4A) using scale 56L₂on the +X side, the pair of X heads 58Lx₁ and 58Lx₂ both outputX-coordinate information. Here, the outputs of the pair of X heads 58Lx₁and 58Lx₂ have the same values. Subsequently, as illustrated in FIG. 5B,when head stage 54 is moved in the −X direction, X head 58Lx₁ will beout of a measurement range of scale 56L₂, and therefore before X heads58Lx₁ is out of the measurement range, the output of X head 58Lx₁ istreated as an invalid output. Consequently, the X-position informationof head stage 54 is obtained on the basis of only the output of X head58Lx₂.

Further, as illustrated in FIG. 5C, when head stage 54 (see FIG. 4A) ismoved further in the −X direction, X head 58Lx₁ faces scale 56L₁ on the−X side. Immediately after coming into a state of capable of performinga measurement operation using scale 56L₁, X head 58Lx₁ outputs theX-position information of head stage 54. However, since the counting ofthe output of X head 58Lx₁ is resumed from an undefined value (or zero),the output of X head 58Lx₁ cannot be used in computation of theX-position information of head stage 54. Consequently, in this state,the linkage processing of the respective outputs of the pair of X heads58Lx₁ and 58Lx₂ is required. Specifically, as the linkage processing,the processing of correcting the output of X head 58Lx₁ that shows theundefined value (or zero) using the output of X head 58Lx₂ (e.g., sothat the outputs show the same value) is performed. The linkageprocessing is completed before head stage 54 is moved further in the −Xdirection and X head 58Lx₂ is out of the measurement range of scale56L₂, as illustrated in FIG. 5D.

Similarly, as illustrated in FIG. 5D, in the case where X head 58Lx₂will be out of the measurement range of scale 56L₂, the output of X head58Lx₂ is treated as an invalid output before X head 58Lx₂ is out of themeasurement range. Consequently, the X-position information of headstage 54 (see FIG. 4A) is obtained on the basis of only the output of Xhead 58Lx₁. Then, as illustrated in FIG. 5E, mask holder 40 head stage54 is moved further in the −X direction, and immediately after each ofthe pair of X heads 58Lx₁ and 58Lx₂ comes into a state capable ofperforming a measurement operation using scale 56L₁, the linkageprocessing using the output of X head 58Lx₁ is performed with respect toX head 58Lx₂. After that, the X-position information of head stage 54 isobtained on the basis of the output of each of the pair of X heads 58Lx₁and 58Lx₂.

Next, the configuration of substrate encoder system 60 will bedescribed. As illustrated in FIG. 1, for example, four Y encoder bases62Y are fixed on the lower surface of optical surface plate 18 a. Notethat, in FIG. 1, two of the four Y encoder bases 62Y are hidden behindthe other two on the depth side of the page surface (see FIG. 3B).Further, for example, below the four Y encoder bases 62Y, a pair of Xencoder bases 62X are disposed. Furthermore, below each of the pair of Xencoder bases 62X, head stage 64 is disposed. Further, short scales 66Sare fixed on the upper surface of substrate holder 24, corresponding toa pair of head stages 64.

As illustrated in FIG. 3B, Y encoder base 62Y is made up of a memberextending in the Y-axis direction. For example, two of the four Yencoder bases 62Y are disposed on the +Y side of projection opticalsystem 16, spaced apart in the X-axis direction, and the other two aredisposed on the −Y side of projection optical system 16, spaced apart inthe X-axis direction. A plurality of Y long encoder scales 66Y(hereinafter, referred to as Y long scales 66Y) are fixed on the lowersurface of Y encoder base 62Y.

Y long scale 66Y is made up of a plate-like (band-like) member that isformed of, for example, a quartz glass and has a rectangular shape inplanar view extending in the Y-axis direction. As illustrated in FIG.4B, Y long scale 66Y is configured of a reflective diffraction grating(a Y grating) having a plurality of grid lines formed at a predeterminedpitch in the Y-axis direction (with the Y-axis direction serving as aperiod direction) and extending in the X-axis direction. Note that,although the grid lines are illustrated in solid lines and Y long scales66Y are illustrated as if facing upward in FIGS. 3B and 4B, theplurality of Y long scales 66Y are disposed with the grating surfacesfacing downward in actuality, as illustrated in FIG. 1.

The grating pitch and the like of Y long scale 66Y may be the same as ormay be different from those of Y scale 56Ly described above (see FIG.4A). Encoder base 62Y described above is formed of a material with athermal expansion coefficient lower than (or equal to) that of Y longscale 66Y so that the grating pitch is prevented from changing due to,for example, the change in temperature and the like.

Referring back to FIG. 3B, X encoder base 62X is made up of a memberextending in the X-axis direction, and is stretched between a pair of Yencoder bases 62Y spaced apart in the X-axis direction. A pair of Xencoder bases 62X are driven with a predetermined stroke synchronouslywith substrate holder 24 in the Y-axis direction, by an X base drivingsystem 84 (see FIG. 6). For example, a mechanical linear guide devicefor straightly guiding X encoder bases 62X in the Y-axis direction isprovided between Y encoder bases 62Y and X encoder base 62X.

A pair of Y long heads 68Y are fixed at each of both end-vicinities of Xencoder base 62X. Y long heads 68Y are encoders heads of a diffractioninterference method similar to long heads 58L described above (see FIG.4A), and supply the position information of X encoder base 62X in theY-axis direction to main controller 90 (see FIG. 6) by irradiating Yscales 66Y with measurement beams and receiving the beams from thescales.

That is, in substrate encoder system 60, for example, four (2×2) Y longheads 68Y and Y long scales 66Y (which differ depending on theY-position of X encoder bases 62X) that correspond to these Y long headsconfigure, for example, four Y long linear encoders 96Ly (see FIG. 6)for obtaining the position information of X encoder bases 62X in theY-axis direction.

Here, as illustrated in FIG. 4B, similarly to long scales 56L describedabove (see FIG. 4A), a plurality of Y long scales 66Y are also disposedat a predetermined spacing in the Y-axis direction. Further, the spacingbetween a pair of Y long heads 68Y is set wider than the spacing betweenY long scales 66Y adjacent to each other. Accordingly, in substrateencoder system 60, at least one of the pair of Y long heads 68Yconstantly faces Y long scale 66Y. Consequently, in substrate encodersystem 60, the position information of X encoder base 62X (see FIG. 3A)can be obtained without interrupting the measurement values. Therefore,also in this case, the linkage processing similar to the linkageprocessing (see FIGS. 5A to 5E) of the head outputs in mask encodersystem 50 described above is performed.

A plurality of X long encoder scales 66X (hereinafter, referred to as Xlong scales 66X) are fixed on the lower surface of X encoder base 62X. Xlong scale 66X is made up of a plate-like (band-like) member that isformed of, for example, a quartz glass and has a rectangular shape inplanar view extending in the X-axis direction. As illustrated in FIG.4C, X long scale 66X is configured of a reflective diffraction grating(an X grating) having a plurality of grid lines formed at apredetermined pitch in the X-axis direction (with the X-axis directionserving as a period direction) and extending in the Y-axis direction.Note that, although grid lines are illustrated in solid lines and X longscales 66X are illustrated as if facing upward in FIGS. 3B, 4B and 4C,the plurality of X long scales 66X are disposed with the gratingsurfaces facing downward in actuality as illustrated in FIG. 1. Notethat, although X long scale 66X has the grid lines formed at apredetermined pitch in the X-axis direction, this is not intended to belimiting, and may have grid lines formed at a predetermined pitch inboth of the X-axis direction and the Y-axis direction. Similarly,although Y long scale 66Y has the grid lines formed at a predeterminedpitch in the Y-axis direction, this is not intended to be limiting, andmay have grid lines formed at a predetermined pitch in both of theX-axis direction and the Y-axis direction.

As illustrated in FIG. 4C, head stage 64 is made up of a plate-likemember with a rectangular shape in planar view and is driven with a longstroke synchronously with substrate holder 24 in the X-axis direction,by a head stage driving system 86 (see FIG. 6) including an actuatorsuch as, for example, a liner motor. For example, a mechanical linearguide device for straightly guiding head stage 64 in the X-axisdirection is provided between head stage 64 and X encoder base 62X.Further, the relative movement of head stage 64 in the Y-axis directionwith respect to encoder base 62X is restricted, and head stage 64 ismoved in the Y-axis direction synchronously with X encoder base 62X whenX encoder base 62X is driven in the Y-axis direction.

A pair of X long heads 68X are fixed to head stage 64. X long heads 68Xare encoder heads of a diffraction interference method similar to longheads 58L described above (see FIG. 4A), and supply the positioninformation of head stage 64 in the X-axis direction to main controller90 (see FIG. 6) by irradiating X long scales 66X with measurement beamsand receiving the beams from the scales.

That is, in substrate encoder system 60, for example, the four (2×2) Xlong heads 68X and X long scales 66X (which differ depending on theX-position of head stages 64) that correspond to these X long headsconfigure, for example, four X long linear encoders 96Lx (see FIG. 6)for obtaining the position information of head stages 64 in the X-axisdirection.

Further, one X short head 68Sx and one Y short head 68Sy (collectivelyreferred to as short heads 68S, as needed) are fixed to head stage 64.Short heads 68S are also encoder heads of a diffraction interferencemethod similar to X long heads 68X described above, and supply therelative position information between substrate holder 24 and head stage64 to main controller 90 (see FIG. 6) by irradiating short scales 66Swith measurement beams and receiving the beams from the scales.

Short scale 66S is substantially the same as short scale 56S (see FIG.3A) fixed to mask holder 40 described above. That is, short scale 66Shas an X scale 66Sx and a Y scale 66Sy. Further, short scale 66S isdisposed slightly shifted relative to X long scale 66X in the Y-axisdirection, but may be disposed at the same Y-position as X long scale66X. Similarly to X encoder base 62X described above, substrate holder24 is also formed of a material with a thermal expansion coefficientlower than (or equal to) that of short scale 66S.

That is, in substrate encoder system 60, for example, the two X shortheads 68Sx and X short scales 66Sx that face these X short headsconfigure, for example, two X short linear encoders 98Sx (see FIG. 6)for obtaining the relative position information between head stage 64and substrate holder 24 in the X-axis direction, and for example, thetwo Y short heads 68Sy and Y short scales 66Sy that face these Y shortheads configure, for example, two Y short linear encoders 98Sy (see FIG.6) for obtaining the relative position information between head stage 64and substrate holder 24 in the Y-axis direction.

Consequently, X base driving system 84 and head stage driving system 86described above (see FIG. 6 for each of them) relatively drive X encoderbases 62X and head stages 64 with respect to substrate holder 24,respectively, synchronously with substrate holder 24 so that themeasurement beams from short heads 68S are prevented from moving offfrom short scales 66X (so that short heads 68S follow short scales 66S).In other words, unless the measurement beams from short heads 68S moveoff from short scales 66S, the positions of substrate holder 24 and headstages 64 at the time of movement do not completely have to be coincidewith each other. That is, in substrate encoder system 60, aconfiguration is employed in which the relative positional shift betweensubstrate holder 24 and head stages 64 is allowed (the positional shiftis compensated) by X short linear encoders 98Sx and Y short linearencoders 98Sy (see FIG. 6).

In FIG. 6, a block diagram is illustrated that shows the input/outputrelationship of main controller 90 that centrally configures the controlsystem of liquid crystal exposure apparatus 10 (see FIG. 1) and performsthe overall control of the respective components. Main controller 90includes a workstation (or a microcomputer) and the like, and performsthe overall control of the respective components of liquid crystalexposure apparatus 10.

In liquid crystal exposure apparatus 10 (see FIG. 1) configured asdescribed above, under the control of main controller 90 (see FIG. 6),mask M is placed onto mask stage device 14 by a mask loader (notillustrated) and also substrate P is loaded onto substrate stage device20 (substrate holder 24) by a substrate loader (not illustrated). Afterthat, main controller 90 implements alignment measurement using analignment detection system (not illustrated), and after the alignmentmeasurement is finished, the exposure operation of a step-and-scanmethod are sequentially performed with respect to a plurality of shotareas set on substrate P.

Since the operations of mask stage device 14 and substrate stage device20 at the time of the exposure operation of step-and-scan methodreferred to above are the same as the operations in a conventionalexposure apparatus, the description thereof will be omitted.

Further, at the time of the exposure operation of step-and-scan methodreferred to above, in mask encoder system 50, a pair of head stages 54are driven in the scan direction, synchronously with the movement(acceleration, movement at a constant speed, and deceleration) of mask Min the scan direction.

Further, at the time of the exposure operation of step-and-scan methodreferred to above, in substrate encoder system 60, as illustrated inFIG. 7A, when substrate P (substrate holder 24) is driven in the X-axisdirection for the scan exposure operation, the pair of head stages 64are driven synchronously with substrate P in the X-axis direction. Onthis occasion, the pair of X encoder bases 62X are in a static state. Onthe other hand, as illustrated in FIG. 7B, when substrate P (substrateholder 24) is driven in the Y-axis direction for inter-shot-areamovement, the pair of head stages 64 are moved integrally with the pairof X encoder bases 62X in the Y-axis direction. Consequently, themeasurement beams from short heads 68S do not move off from short scales66S.

As is described above, according to liquid crystal exposure apparatus 10related to the present embodiment, in each of mask encoder system 50 forobtaining the position information of mask M within the XY plane andsubstrate encoder system 60 for obtaining the position information ofsubstrate P within the XY plane (see FIG. 1 for each of them), theoptical path length of the measurement beam that is irradiated to thecorresponding scale is short, and therefore, the influence of airfluctuation can be reduced, for example, compared to a conventionalinterferometer system. Consequently, the positioning accuracy of mask Mand substrate P is improved. Further, since the influence of airfluctuation is small, a partial air conditioning equipment that isessential in the case of using the conventional interferometer systemcan be omitted, which allows the cost to be reduced.

Moreover, in the case of using the interferometer system, a large andheavy bar mirror is required to be equipped in mask stage device 14 andsubstrate stage device 20. However, since such a bar mirror isunnecessary in mask encoder system 50 and substrate encoder system 60related to the present embodiment, a system including mask holder 40 anda system including substrate holder 24 are each downsized and lightenedand also the better weight balance is obtained, and accordingly theposition controllability of mask M and substrate P is improved. Further,the points to be adjusted can be decreased, compared to the case ofusing the interferometer system, which leads to the cost reduction ofmask stage device 14 and substrate stage device 20 and further leads tothe improved maintainability. Furthermore, the adjustment at the time ofassembly becomes easier (or unnecessary).

Further, in substrate encoder system 60 related to the presentembodiment, since a configuration is employed in which, for example, theY-position information of substrate P is obtained by driving the pair ofhead stages 64 synchronously with substrate P (causing the pair of headstages 64 to follow substrate P) in the Y-axis direction, a scaleextending in the Y-axis direction needs not be disposed on the substratestage device 20 side (or a plurality of heads needs not be arrayed inthe Y-axis direction on the apparatus main body 18 side). Consequently,the configuration of the substrate position measurement system can besimple, which allows the cost to be reduced.

Further, in mask encoder system 50 related to the present embodiment,since a configuration is employed in which the position information ofmask holder 40 within the XY plane is obtained while the outputs of apair of encoder heads (X heads 58Lx, Y heads 58Ly) adjacent to eachother are switched as needed depending on the X-position of mask holder40, the position information of mask holder 40 can be obtained withoutinterruption even if a plurality of scales 56L are disposed at apredetermined spacing (spaced apart from each other) in the X-axisdirection. Consequently, a scale with a length equivalent to themovement stroke of mask holder 40 needs not be prepared, which allowsthe cost to be reduced, and mask encoder system 50 is suitable, inparticular, for liquid crystal exposure apparatus 10 using mask M of alarge size as in the present embodiment. Similarly, also in substrateencoder system 60 related to the present embodiment, since a pluralityof scales 66X are disposed at a predetermined spacing in the X-axisdirection and a plurality of scales 66Y are disposed at a predeterminedspacing in the Y-axis direction, a scale with a length equivalent to themovement stroke of substrate P needs not be prepared, and substrateencoder system 60 is suitable for liquid crystal exposure apparatus 10using substrate P of a large size.

Further, although short scales 66S in the present embodiment are fixedon the upper surface of substrate holder 24, this is not intended to belimiting, and may be fixed on the lower surface of substrate holder 24.In such a case, head stage 64 may be configured of two stages that are ahead stage 64 a and a head stage 64 b. Head stage 64 a is disposed toface X encoder base 62X, and head stage 64 b is disposed to face shortscales 66S fixed on the lower surface of substrate holder 24. In otherwords, head stage 64 a is disposed between optical surface plate 18 aand substrate holder 24, and head stage 64 b is disposed below substrateholder 24. In this case, head stage 64 a and head stage 64 b aresynchronously moved within a two-dimensional plane including the X-axisdirection and the Y-axis direction. Note that head stage 64 a and headstage 64 b may mechanically be coupled, or electrical control may beperformed so that head stage 64 a and head stage 64 b are synchronouslydriven. Note that, although the explanation is given that head stage 64a and head stage 64 b are synchronously moved, this means that headstage 64 a and head stage 64 b are moved in a state of roughlymaintaining the relative positional relationship between head stage 64 aand head stage 64 b, and is not limited to the case of moving head stage64 a and head stage 64 b in a state where the positional relationshipbetween head stage 64 a and head stage 64 b, their movement directions,and their movement velocities strictly coincide with each other.

Further, in substrate encoder system 60 related to the presentembodiment, although X encoder base 62X is disposed below Y encoder base62Y, X encoder base 62X may be provided at head stage 64. As illustratedin FIG. 11, head stage 64 may be configured of two stages that are headstage 64A and head stage 64B. Y heads 68Y are disposed on the uppersurface of head stage 64A, and X long scales 66X are disposed on thelower surface of head stage 64A. X heads 68X are disposed on the uppersurface of head stage 64B, and short heads 68S are disposed on the lowersurface of head stage 64B. When substrate holder 24 is moved in theX-axis direction, head stage 64B is moved in the X-axis directionsynchronously with the movement of substrate holder 24. Note that headstage 64A is not moved in either the X-axis direction or the Y-axisdirection. Further, when substrate holder 24 is moved in the Y-axisdirection, head stage 64A and head stage 64B are synchronously moved inthe Y-axis direction so as to be synchronized with the movement ofsubstrate holder 24.

Second Embodiment

Next, a liquid crystal exposure apparatus related to a second embodimentwill be described using FIG. 8. The configuration of the liquid crystalexposure apparatus related to the second embodiment is the same as thefirst embodiment described above except that the configuration of asubstrate encoder system 160 is different. Therefore, only thedifferences will be described below, and elements that have the sameconfigurations and functions as those in the first embodiment describedabove will be provided with the same reference signs as those in thefirst embodiment described above, and the description thereof will beomitted.

In substrate encoder system 160 in the present second embodiment, theconfiguration of a drive system for driving short head 68S is different,compared to the first embodiment described above. That is, in the firstembodiment described above, as illustrated in FIG. 3C 3B, a pair of Yencoder bases 62Y (fixed) and one X encoder base 62X (movable) stretchedbetween the pair of Y encoder bases 62Y are used for one short head 68S,whereas in the present second embodiment, as illustrated in FIG. 8, apair of X encoder bases 62X (fixed) and one Y encoder base 62Y (movable)stretched between the pair of X encoder bases 62X are used. The presentsecond embodiment can also obtain the similar effect to the firstembodiment described above.

Note that the respective configurations of the first embodiment and thesecond embodiment are merely examples, and can be changed as needed. Forexample, image sensors (cameras) or fiducial marks are attached to headstages 54 and 64, and calibration related to the projection lenses maybe performed using the image sensors. In this case, since thecalibration referred to above can be performed without using mask holder40 and substrate holder 24, good efficient is obtained.

Further, in substrate encoder system 60 in the embodiments describedabove, although the relative position information between head stages 64and substrate holder 24 is obtained by the encoder system that includesshort heads 68S attached to head stages 64 and short scales 66X fixed tosubstrate holder 24, this is not intended to be limiting. Since arelative movement amount between head stages 64 and substrate holder 24is small, the relative position information between head stages 64 andsubstrate holder 24 may be obtained by, for example, forming marks atsubstrate holder 24 and attaching image sensors to head stages 64, andobserving the marks with the image sensors and performing the imageprocessing with high speed.

Further, the arrangement of each of the scales and the headscorresponding thereto may be reversed in each of the embodimentsdescribed above. For example, short heads 68S may be fixed to substrateholder 24 and short scales 66S may be fixed to head stages 64.

Further, as illustrated in FIG. 9, the distance between the pair of Xlong heads 68X that head stage 64 has may be measured by a sensor 166and the output of substrate encoder system 60 may be corrected using themeasurement values. The type of sensor 166 is not particularly limited,and for example, a laser interferometer or the like can be used. As isdescribed above, the linkage processing of the outputs of the pair ofencoder heads is performed in substrate encoder system 60, and it is theprecondition in this linkage processing that the distance between thepair of encoder heads is known and invariable. Therefore, head stage 64to which each of the heads is attached is made of, for example, amaterial less affected by thermal expansion and the like. However, theposition information of substrate P can be obtained with high accuracyby measuring the distance between the encoder heads as in the presentmodified example, even if head stage 64 is deformed (the distancebetween the pair of encoder heads is changed). Similarly, the distancebetween a pair of X long heads 58Lx that head stage 54 of mask encodersystem 50 has and the distance between a pair of Y long heads 68Y fixedto X encoder base 62X of substrate encoder system 60 may be measured.Further, the relative positional relationships between all (e.g., eightin total in the present embodiment) of the heads (the pairs of downwardheads 66 x and 66 y, and the pairs of upward heads 64 x and 64 y) thatstage 64 has may be each measured, and the measurement values may becorrected.

Further, as is described above, a calibration operation may be performedin which the distance between a pair of X long heads 68X that head stage64 has is measured as needed (e.g. at every substrate exchange).Further, separately from a calibration point for performing theforegoing measurement of the distances between the heads, anothercalibration point for performing the positioning of the origins of therespective outputs of mask encoder system 50 and substrate encodersystem 60 may be provided. For example, positioning marks for performingthe positioning of the origins may be disposed on the extended lines of(on the outer side of) the plurality of scales 56L, 66Y and 66X, or maybe disposed between a pair of scales 56L adjacent to each other, a pairof scales 66Y adjacent to each other and a pair of scales 66X adjacentto each other, or may be formed in scales 56L, 66Y and 66X.

Further, the amount of tilt (inclination in the ex direction and the θydirection) of each of head stages 54 and 64 and X encoder base 62X withrespect to the horizontal plane may be obtained, and the output ofsubstrate encoder system 60 may be corrected in accordance with the tiltamount (the inclined amount of the optical axis of each of encoder heads58L, 58S, 68Y, 68X and 68S). As a measurement system, as illustrated inFIG. 10, a measurement system in which a plurality of Z sensors 64 z areattached to a target object (although the target object is X encoderbase 62X in FIG. 10, head stage 64 may be the target object) and thetilt amount of the target object is obtained with Y encoder base 62Y (orupper mount section 18 a) serving as a reference can be used.Alternatively, a biaxial laser interferometer 264 may be provided, andthe tilt amount (the inclination amount in the θx direction and the θydirection) and the rotation amount (the rotation amount in the θzdirection) of the target object (although the target object is headstage 64 in FIG. 10, X encoder base 62X may be the target object) may beobtained. Further, the tilt amount of each of heads 58L, 58S, 68Y, 68Xand 68S may be individually measured.

Further, the case has been described where a plurality of long scales56L are disposed spaced apart in the X-axis direction in mask encodersystem 50, and a plurality of Y long scales 66Y are disposed spacedapart in the Y-axis direction and a plurality of X long scales 66X aredisposed spaced apart in the X-axis direction in substrate encodersystem 60, the number of the scales are not limited thereto, but may bechanged as needed depending on, for example, the size of mask M, thesize of substrate P or the movement strokes. Further, a plurality ofscales do not necessarily have to be disposed spaced apart, and onelonger scale may be used.

Further, in the case of providing a plurality of scales, the respectivelengths of the scales may be different from one another. For example,the length of the scale extending in the X-axis direction is set longerthan the length of a shot area in the X-axis direction, and thereby thelinkage processing at the time of the scanning exposure operation can beavoided. The same applies to the scale extending in the Y-axisdirection. Further, in order to cope with the change in the number ofthe shot areas (for example, in the case of preparing four areas and thecase of preparing six areas), a scale disposed on one side of projectionoptical system 16 and a scale disposed on the other side may have therespective lengths different from each other.

Further, although the case has been described where X long scale 56Lxand Y long scale 56Ly are independently formed on the surface of longscale 56L, this is not intended to be limiting, and for example, an XYtwo-dimensional scale may be used. In this case, as the encoder head, anXY two-dimensional head can be used. The same applies to the short scaleand the short head. Although the case of using the encoder system of adiffraction interference method has been described, this is not intendedto be limiting, and the other encoder such as an encoder of a so-calledpick-up method and an encoder of a magnetic method can be used, and aso-called scan encoder that is disclosed in, for example, U.S. Pat. No.6,639,686 and the like can also be used.

Further, although Y encoder base 62Y that has Y long scales 66Y isconfigured to be directly attached to the lower surface of opticalsurface plate 18 a, this is not intended to be limiting, and apredetermined base member may be disposed in a suspended manner in astate spaced apart from the lower surface of optical surface plate 18 a.

Further, substrate stage device 20 only has to drive substrate P with along stroke at least along the horizontal plane, and the finepositioning in the directions of six degrees of freedom needs not beperformed according to the circumstances. The substrate encoder systemrelated to each of the embodiments described above can also be suitablyapplied to such a two-dimensional stage device.

Further, it has been descried that, in the case where the pair of X longheads 58Lx both face the long scale, main controller 90 (see FIG. 6)obtains the X-position information of head stage 54 on the basis of theaveraged value of the outputs of long heads 58Lx, but this is notintended to be limiting. By providing the master-slave relationship tothe pair of X long heads 58Lx, the X-position information of head stage54 may be obtained on the basis of only the value of one X long head58Lx.

Further, in the case where a plurality of scale groups (scale rows) onoptical surface plate 18 a, in each of which a plurality of scales arearranged in line in the X-axis direction via a gap of a predeterminedspacing, are disposed at different positions spaced from each other inthe Y-axis direction (e.g., the position on one side (the +Y side) andthe position on the other side (the −Y side) with respect to projectionoptical system 16), the positions of the gaps of the predeterminedspacing described above may be disposed not to overlap in the X-axisdirection among the plurality of scale rows. By disposing the pluralityof scale rows in this manner, the heads placed corresponding to therespective scale rows can be prevented from being simultaneously locatedoutside the measurement range (in other words, both the heads can beprevented from simultaneously facing the gaps).

Further, in each of the embodiments described above, although there isthe description that X encoder bases 62X or head stages 64 are movedsynchronously with substrate holder 24, this means that X encoder bases62X or head stages 64 are moved in a state of roughly maintaining therelative positional relationship with substrate holder 24, and is notlimited to the case where X encoder bases 62X or head stages 64 andsubstrate holder 24 are moved in a state where the positionalrelationship between X encoder bases 62X or head stages 64 and substrateholder 24, their movement directions, and their movement velocitiesstrictly coincide with each other.

Further, in the case where a plurality of scale groups (scale rows) onoptical surface plate 18 a, in each of which a plurality of scales arearranged in line in the X-axis direction via a gap of a predeterminedspacing, are disposed at different positions spaced from each other inthe Y-axis direction (e.g., the position on one side (the +Y side) andthe position on the other side (the −Y side) with respect to projectionoptical system 16), a configuration may be employed in which theseplurality of scale groups (the plurality of scales rows) can be usedproperly depending on the arrangement of shots (the shot map) on thesubstrate. For example, by making the length of each of the plurality ofscale rows as a whole different between the scale rows, the differentshot maps can be coped with, and the change in the number of shot areasformed on the substrate such as the case of preparing four areas and thecase of preparing six areas can be coped with. Along with disposing theplurality of scales rows in this manner, by making the respectivepositions of gaps in the scales rows different from each other in theX-axis direction, the heads respectively corresponding to the pluralityof scale rows do not simultaneously located outside the measurementrange, and therefore the number of sensors whose measurement values areregarded as undefined values can be reduced in the linkage processing,which allows the linkage processing to be performed with high accuracy.

Further, in the scale groups (the scale rows) on optical surface plate18 a, in each of which a plurality of scales are arranged in line via agap of a predetermined spacing in the X-axis direction, the length ofone scale (a pattern for X-axis measurement) in the X-axis direction maybe set to a length which allows the measurement corresponding to thelength of one shot area to be continuously performed (a length alongwhich a device pattern is formed on a substrate by being irradiated whenscan exposure is performed while moving the substrate on a substrateholder in the X-axis direction). By setting the length of one scale inthe X-axis direction in this manner, the transfer control of heads withrespect to a plurality of scales does not have to be performed duringthe scan exposure of one shot area, and therefore the positionmeasurement (the position control) of substrate P (the substrate holder)during the scan exposure can be performed easily.

Further, in the scale groups (the scale rows) on mask holder 40, in eachof which a plurality of scales are arranged in line via a gap of apredetermined spacing in the X-axis direction, the scales with the samelength are arranged in line in the embodiments described above, but thescales with lengths different from each other may be arranged in line.For example, in a scale row on mask holder 40, the length in the X-axisdirection of scales disposed in the central part may be set physicallylonger than the length in the X-axis direction of scales disposed nearboth ends in the X-axis direction (scales disposed at the respectiveends in a scale row).

Further, in each of the embodiments described above, although a pair ofX heads and a pair of Y heads are disposed in line in the X-axisdirection so as to be each paired (the X heads and the Y heads aredisposed in the same position in the X-axis direction), the X heads andthe Y heads may be disposed relatively shifted in the X-axis direction.

Further, in the case where, while a given head stage 54 and a scale rowcorresponding thereto (a scale row in which a plurality of scales arearranged in line via a predetermined gap in a predetermined direction)are being relatively moved in the X-axis direction, a given set of headsin head stage 54 simultaneously face the gap between the foregoingscales, and then simultaneously face another scale, the measurementinitial values of the heads that have transferred need to be computed.On this computation, by using the outputs of a remaining set of heads inhead stage 54 that are different from the heads that have transferredand the output of yet-another head that is different from these heads (ahead spaced apart in the X-axis direction and disposed at a positionwhose distance from the heads having moved off from the scale is shorterthan the scale length), the initial values on the transfer of the headsthat have transferred may be computed. The foregoing yet-another headmay be either of a head for position measurement in the X-axis directionor a head for position measurement in the Y-axis direction.

Further, in substrate encoder system 60 related to each of theembodiments described above, in order to acquire the positioninformation of substrate stage device 20 while substrate stage device 20is moved to a substrate exchange position with respect to the substrateloader, a scale for substrate exchange may be provided at substratestage device 20 or another stage device, and the position information ofsubstrate stage device 20 may be acquired using the downward heads (suchas X heads 68 sx). Alternatively, a head for substrate exchange may beprovided at substrate stage device 20 or another stage device, and theposition information of substrate stage device 20 may be acquired bymeasuring the scales or a scale for substrate exchange.

Further, in mask encoder system 50 related to each of the embodimentsdescribed above, in order to acquire the position information of maskstage device 14 while mask stage device 14 is moved to a mask exchangeposition with respect to the mask loader, a scale for mask exchange maybe provided at mask stage device 14 or another stage device, and theposition information of mask stage device 14 may be acquired using headunit stage 54. Further, another position measurement system (e.g., markson the stage and an observing system for observing the marks) differentfrom the encoder system may be provided and thereby the exchangeposition control (management) of the stage may be performed.

Further, the illumination light may be ultraviolet light such as an ArFexcimer laser beam (with a wavelength of 193 nm) or a KrF excimer laserbeam (with a wavelength of 248 nm), or vacuum ultraviolet light such asan F₂ laser beam (with a wavelength of 157 nm). Further, as theillumination light, a harmonic wave, which is obtained by amplifying asingle-wavelength laser beam in the infrared or visible range emittedby, for example, a DFB semiconductor laser or a fiber laser, with afiber amplifier doped with, for example, erbium (or both erbium andytterbium), and by converting the wavelength into ultraviolet lightusing a nonlinear optical crystal, may also be used. Further, a solidlaser (with a wavelength: 355 nm and 266 nm) or the like may be used.

Further, although the case has been described where projection opticalsystem 16 is a projection optical system of a multi-lens method equippedwith a plurality of optical systems, the number of the projectionoptical systems is not limited thereto, and one or more of theprojection optical systems have only to be provided. Further, theprojection optical system is not limited to the projection opticalsystem of a multi-lens method, but may be a projection optical systemusing an Offner-type large mirror or the like. Further, projectionoptical system 16 may be a magnifying system or a reduction system.

Further, the use of the exposure apparatus is not limited to theexposure apparatus for liquid crystal display devices that transfers aliquid crystal display device pattern onto a square-shaped glass plate,but can be widely applied also to, for example, an exposure apparatusfor manufacturing organic EL (Electro-Luminescence) panels, an exposureapparatus for manufacturing semiconductor devices, and an exposureapparatus for manufacturing thin-film magnetic heads, micromachines, DNAchips or the like. Further, each of the embodiments described above canalso be applied to an exposure apparatus that transfers a circuitpattern onto a glass substrate or a silicon wafer or the like, not onlywhen producing microdevices such as semiconductor devices, but also whenproducing a mask or a reticle used in an exposure apparatus such as anoptical exposure apparatus, an EUV exposure apparatus, an X-ray exposureapparatus, or an electron beam exposure apparatus.

Further, an object serving as an exposure target is not limited to aglass plate, but may be other objects such as, for example, a wafer, aceramic substrate, a film member, or a mask blank. Further, in the casewhere an object to be exposed is a substrate for flat-panel display, thethickness of the substrate is not particularly limited, and for example,a film-like member (a sheet-like member with flexibility) is alsoincluded. Note that the exposure apparatus of the present embodiments isespecially effective in the case where a substrate having a side or adiagonal line with a length of 500 mm or greater is an object to beexposed.

Electronic devices such as liquid crystal display devices (orsemiconductor devices) are manufactured through the steps such as: astep in which the function/performance design of a device is performed;a step in which a mask (or a reticle) based on the design step ismanufactured; a step in which a glass substrate (or a wafer) ismanufactured; a lithography step in which a pattern of the mask (thereticle) is transferred onto the glass substrate with the exposureapparatus in each of the embodiments described above and the exposuremethod thereof; a development step in which the glass substrate that hasbeen exposed is developed; an etching step in which an exposed member ofthe other section than a section where resist remains is removed byetching; a resist removal step in which the resist that is no longernecessary when etching is completed is removed; a device assembly step;and an inspection step. In this case, in the lithography step, theexposure method described previously is implemented using the exposureapparatus in the embodiments described above and a device pattern isformed on the glass substrate, and therefore, the devices with a highintegration degree can be manufactured with high productivity.

Incidentally, the disclosures of all the U.S. patent applicationPublications and the U.S. patents related to exposure apparatuses andthe like that are cited in the embodiments described above are eachincorporated herein by reference.

INDUSTRIAL APPLICABILITY

As is described so far, the exposure apparatus and the exposure methodof the present invention are suitable for exposing objects withillumination light. Further, the manufacturing method of flat-paneldisplays of the present invention is suitable for production offlat-panel displays. Further, the device manufacturing method of thepresent invention is suitable for production of microdevices.

REFERENCE SIGNS LIST

-   10 . . . liquid crystal exposure apparatus,-   14 . . . mask stage device,-   20 . . . substrate stage device,-   24 . . . substrate holder,-   40 . . . mask holder,-   50 . . . mask encoder system,-   54 . . . head stage,-   60 . . . substrate encoder system,-   64 . . . head stage,-   90 . . . main controller,-   M . . . mask,-   P . . . substrate.

The invention claimed is:
 1. An exposure apparatus that exposes anobject with an illumination light via a projection optical system, theapparatus comprising: a frame member that supports the projectionoptical system; a first movable body that is disposed below theprojection optical system, and holds the object; a measurement sectionthat measures position information of the first movable body withrespect to the frame member; and a first drive section that moves thefirst movable body in a first direction and a second direction based onthe position information, the first direction and the second directionbeing orthogonal to each other within a predetermined plane orthogonalto an optical axis of the projection optical system, wherein themeasurement section has a first scale having a length sufficient tomeasure a movable distance of the first movable body in the firstdirection, a second scale having a length sufficient to measure amovable distance of the first movable body in the second direction, andprovided at the frame member, a first head capable of measuring aposition of the first movable body with respect to the first scale inthe first direction, a second head provided at the first scale, andcapable of measuring a position of the first scale in the seconddirection in a state facing the second scale, and a second drive sectionthat relatively moves the first scale with respect to the second scalein the second direction while maintaining a facing state between thesecond head and the second scale.
 2. The exposure apparatus according toclaim 1, further comprising: a second movable body provided with thefirst head and movable within the predetermined plane; and a third drivesection that moves the second movable body in the first and the seconddirections, wherein the measurement section has a detecting section thatdetects a detected section provided at the first movable body, the thirddrive section moves the second movable body based on a detection resultof the detected section by the detecting section supported by the secondmovable body, and the measurement section measures the positioninformation of the first movable body based on the detection result. 3.The exposure apparatus according to claim 2, wherein the detectedsection is a third scale having a grating area, and the detectingsection is a third head that irradiates the third scale with ameasurement beam, and measurement information of the third head themeasurement beam of which is irradiated on the third scale serves as thedetection result.
 4. The exposure apparatus according to claim 3,wherein the third scale is shorter than the first scale and the secondscale.
 5. The exposure apparatus according to claim 2, wherein the thirddrive section moves the second movable body in the first direction tofollow the first movable body that is moved in the first direction bythe first drive section, while keeping a facing state between the firstscale and the first head and a facing state between the third scale andthe third head.
 6. The exposure apparatus according to claim 2, whereinthe third drive section moves the second movable body in the seconddirection to follow the first movable body that is moved in the seconddirection by the first drive section, while keeping a facing statebetween the first scale and the first head and a facing state betweenthe third scale and the third head, and the second drive section movesthe second scale with respect to the first scale so that the facingstate between the second head and the second scale is maintained.
 7. Theexposure apparatus according to claim 1, further comprising: a formingdevice having a pattern holding body that holds a predetermined patternand a fourth drive section that drives the pattern holding body in thefirst direction, the forming device forming the predetermined pattern onthe object via the pattern holding body using an energy beam.
 8. Theexposure apparatus according to claim 7, wherein the object is asubstrate used in a flat-panel display.
 9. The exposure apparatusaccording to claim 8, wherein the substrate has at least a side or adiagonal line with a length of 500 mm or greater.
 10. A manufacturingmethod of a flat-panel display, comprising: exposing the object usingthe exposure apparatus according to claim 8; and developing the objectthat has been exposed.
 11. A device manufacturing method, comprising:exposing the object using the exposure apparatus according to claim 7;and developing the object that has been exposed.
 12. An exposure methodof exposing an object with an illumination light via a projectionoptical system, the method comprising: measuring position information ofa first movable body with respect to the projection optical system by ameasurement section, the first movable body being disposed below theprojection optical system and holding the object; and moving the firstmovable body in a first direction and a second direction based on theposition information, the first direction and the second direction beingorthogonal to each other within a predetermined plane orthogonal to anoptical axis of the projection optical system, wherein the measurementsection has a first scale having a length sufficient to measure amovable distance of the first movable body in the first direction, asecond scale having a length sufficient to measure a movable distance ofthe first movable body in the second direction, and provided at a framemember that supports the projection optical system, a first head capableof measuring a position of the first movable body with respect to thefirst scale in the first direction, a second head provided at the firstscale, and capable of measuring a position of the first scale in thesecond direction in a state facing the second scale, and a second drivesection that relatively moves the first scale with respect to the secondscale in the second direction while maintaining a facing state betweenthe second head and the second scale.
 13. The exposure method accordingto claim 12, further comprising: moving a second movable body providedwith the first head in the first and the second directions, wherein inthe moving the second movable body, the second movable body is movedbased on a detection result of a detected section by a detectingsection, the detected section being provided at the first movable body,and the detecting section being supported by the second movable body,and in the moving the first movable body, the first movable body ismoved based on the position information obtained based on the detectionresult.
 14. The exposure method according to claim 13, wherein in themoving the second movable body, measurement information of a third headserves as the detection result, the third head being provided at thesecond movable body and irradiating a third scale with a measurementbeam, the third head being the detecting section and the third scalebeing the detected section.